The present invention relates to a disk array apparatus.
In the disk array apparatus, a large number of disk drives of a magnetic-type or an optical-type are contained within a housing to improve the reliability in data reservation. Those disk array apparatuses are connected through a high-speed network for exclusive use thereof, and they are operated by means of management software in the form of, SAM (Storage Area Network), NAS (Network Attached Storage), or an independent RAID (Redundant Array of Inexpensive Disks), for example.
Each of those disk drives, to be installed into those disk array apparatuses, is arranged to include a disk main body, comprising a magnetic disk, a drive motor, an actuator, etc., and connectors for use of electronic parts for control, etc. Main heat-generation sources in the disk drive include the drive motor, the actuator, and the electronic parts for control, in the form of a LSI. Heat generated from those parts is removed using cooling airflow generated by a cooling fan, which is attached on the housing of the disk array. If cooling capacity is deteriorated, the temperature of the disk drive goes up, generating temperature unevenness among the plurality of disk drives and increasing the possibility of erroneous operations or deteriorating reliability.
For example, the unevenness in temperature among the disk drives may cause a shift in timing of the electronic parts; i.e., a possibility of causing defects in the operation of the controller of the disk drive, or generating a delay in the time for data transmission. Also, a temperature increase in the disk drive may cause deterioration in a lubrication layer pasted upon the disk surface, and the disk can therefore be easily damaged.
Also, the magnetic disk, the drive motor, or the actuator, etc., included within an inside of the disk drive, defines an operating portion, and also defines a noise generating portion, at the same time. When installing a large number of disk drives, each having such a noise source, the probability of increased noises generated therefrom rises. Also, even noises generated from the fan for driving an airflow within the disk array apparatus cannot be neglected.
Consequently, within the disk array apparatus, there are two problems to be solved. One is to obtain equal cooling of the disk drives, and the other is to silence the noises of the disk drives and in the entire disk array apparatus.
With a conventional disk array apparatus, mounting the disk drives and the controller circuit on the same surface on a board is already known to provide an air-guide plate, thereby dividing the cooling airflow passages for the disk drives and the controller circuit (please see Japanese Patent Laid-Open No. HEI9-274794).
Also, with the conventional disk array apparatus, an arrangement is made to separate the airflow passage for the disk drives therein, and the airflow passage for the controller circuit therein, so as to equalize the cooling therebetween (please see Japanese Patent Laid-Open No. 2001-338486).
Further, with the conventional disk array apparatus, arranging the disk drives in a zigzag manner is already disclosed (please see Japanese Patent Laid-Open No. HEI5-54626).
Also, with the magnetic disk apparatus, a cooling controller plate for increasing the velocity of airflow passing by the side of a printed board is already disclosed(please see Japanese Patent Laid-Open No. 2001-344961).
With the conventional technology described in Japanese Patent Laid-Open No. HEI 9-274731, since the disk drives and the controller are mounted on the same board, the number of the disk drives which can be installed therein is restricted. Also, there is no problem in equalizing the temperature distribution among the disk drives.
With the conventional technology described in Japanese Patent Laid-Open No. 2001-338686, though the disk drives and the controller are mounted on the same board, and there is no problem in equalizing the temperature distribution among the disk drives as a plurality of the disk drives are installed aligned with the airflow direction.
With the conventional technology described in Japanese Patent Laid-Open No. HEI5-54626, although flow resistance is increased, because of acceleration upon mixing of the cooling air flowing on side surfaces of the disk drives, an improvement of the cooling characteristics of the disk drives can be obtained. However, when the disk drives are disposed within the cooling airflow path by a large number thereof, because of a large space above the disk drives, there is a problem that the cooling air downstream passes through the space above the disk drives, in particular in the zigzag arrangement where the flow resistance is large. Therefore, there is no problem in equalizing the temperature distribution among the disk drives.
With the conventional technology described in Japanese Patent Laid Open No. 2001-344961, although an improvement can be obtained in the cooling performance of the disk drive by itself, there is no disclosure of the structures for cooling a group of the disk drives as a whole, in particular, when a plurality of disk drives is disposed in the downstream side. Therefore, there is no problem of equalizing the temperature distribution among the disk drives.
Also, with those conventional technologies disclosed in the above Patent Documents, the structures for reducing the noises generated within the disk array apparatus are also disclosed.